Mercury-arc rectifier



' MERCURY ARC RECTIFIER Filed March 16, 1928 lnyentoqz Ohmstuan Kramer:

His Arjcorrwegv Patented Apr. 29, 1930 PATENT FFICE CHRISTIAN KRAMER, OFBERLIN -PA1\TKOW, GERMANY, ASSIGNOR TO GENERAL ELEC- TRIO COMPANY, ACORIPORATION" OF NEW YORK MERCURY-ARC RECTIFIER Application filed March16, 1928, Serial No. 262,279, and in. Germany July 23, 1927.

My invention relates to electric discharge devices and more particularlyto' large mercury-arc rectifiers of the type used for transmittingcurrent between alternating and di- 5 rect current power systems. Theprincipal object of this invention is to provide an improved arrangementof the rectifier and its auxiliary apparatus.

The mercury-arc rectifiers used for power purposes commonly consist ofan evacuated metal tank, or container into which the electrodes aresealed, supported on a steel frame work. To take careof leakage throughthe seals and also gases that are generated during operation of therectifier, each rectifier is equipped with an evacuating equipmentconsisting of a condensation vacuum pump, an intermediate vacuum chamberand a second vacuum pump. These pumps and chamber, as hitherto arranged,occupy considerable floor space and leave the space underneath therectifier, unoccupied. In accordance with my invention the intermediatevacuum chamber is constructed as one or more of the supports for therectifier, the second vacuum pump is mounted underneath the rectifierand the whole assembly is mounted'on a portable base.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings, and itsscope will be pointed out in the appended claims.

Referring to the drawing, Fig. 1, is a diagrammatic view of aconventional mercuryarc rectifier with its vacuum pumps, valves and theintermediate vacuum chamber. Fig. 2 isa front view of a rectifierembodying my invention.

Fig. 1 indicates a container 10 supported on a framework 11. Acondensation vacuum pump 12 is connected to the container 10 throughpipe 13 in which valve 14 and vacuum indicator 15 may be connected. Thecondensation vacuum pump is supported from the container 10 and ispreferablyv of the type disclosed in Letters Patent of Irving Langmuir,No. 1,393,550. This pump discharges into an intermediate vacuum chamber16 through a one way valve 17 which isso constructed that it preventsgases reentering the container 10 in case the condensation pump fails.Another vacuum pump 18 often referred to as the roughing pump evacuateschamber 16, through pipe 19 and valve 20. In practice it is found thatafter the first complete evacuation of the container, pump, 18 may beoperated intermittently, that is, pump 12 discharges so small an amountof gases into the chamber 16 that considerable time elapses before thepressure therein is high enough to warrant operation of pump 18.

Fig. 2 shows container 10 supported on columns 20 which are hollow andare used as the intermediate vacuum chambers. They are connected to pump18 and to. each other through pipe 21 and valves 22. The condensationpump 12 is mounted on the side of container 10 and is connected throughvalve 14to the container and through trap 27, pipe 24 and valve 23 tochamber 20. Anotherpipe 25 is shown connected to trap 27. This pipebranches off and leads to sealing chambers of the electrodes 26 and 28.This type of sealis disclosed in my Letters Patent No. 1,643,216.

The columns 20 may be of any suitable number and convenient size, one-ormore of which may be used as preliminary vacuum chambers, depending uponthe volumerequired. These chambers and pump 18 may then be mounted on abase 29 and rollers 30 thus making a compact portable rectifier unit.

l/Vhat I claim as new and desire to secure by Letters Patent of theUnited States is: 1. An electric discharge device comprising anevacuated container and electrodes sealed therein, a hollow support forsaid container, a plurality of vaccuum pumps adapted to evacuate saidcontainer, said support being arranged to form a chamber connectedbetween said pumps,.

2. A mercury-arc rectifier, a plurality of vacuum pumps adapted toevacuate said rectifier, and a rectifier support arranged to form avacuum chamber connected between said pumps.

3. In combination a mercury-arc rectifier,

supporting members. therefor comprising" chambers, a plurality of Vacuumpumps, one of said pumps being mounted on said rectifier and operativelyconnected between said rectifier and said chambers, a second Vacuum pumplocated underneath said rectifier and operatively connected to saidchambers, and a portable base upon Which said chambers and said secondvacuum pump are mounted. In witness whereof, I have hereunto set my handthis 24th day or" February. 1928.

' CHRISTIAN KRAMER.

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